Macro Calculator
Calculate your optimal daily macronutrient intake based on your body stats, activity level, and fitness goals
Your age affects metabolic rate
Enter your current body weight
Enter your height for accurate BMR calculation
Split your daily macros across this many meals
Calculate Your Macros
Enter your details, select a diet preset, and click calculate to see your personalized macronutrient targets.
How to Use the Macro Calculator
Enter Your Body Stats
Select your sex, enter your age, choose imperial or metric units, and input your weight and height. If you already know your daily calorie needs, switch to Direct Calorie Input mode instead and enter your TDEE directly.
Set Activity Level and Goal
Choose the activity level that best matches your typical week, from sedentary to extra active. Then select your weight goal: maintain, lose weight at a mild, standard, or extreme rate, or gain weight at a mild, standard, or extreme rate.
Choose a Diet Preset or Custom Ratios
Select from six popular diet presets (Balanced, Low Fat, Low Carb, High Protein, Ketogenic, Zone) or create a custom ratio by entering your own protein, carb, and fat percentages that sum to 100%. Use Advanced Settings to change the BMR formula.
Review Your Results
View your daily macro targets in grams and calories, see the visual donut chart of your macro split, compare diet presets side-by-side, and check your per-meal breakdown. Export results to CSV or print them for your records.
Frequently Asked Questions
What are macros and why do they matter for weight loss?
Macros, short for macronutrients, are the three main categories of nutrients your body needs in large quantities: protein, carbohydrates, and fat. While total calorie intake determines whether you gain or lose weight, macronutrient ratios affect your body composition, energy levels, satiety, and metabolic health. For example, higher protein intake during a calorie deficit helps preserve lean muscle mass and keeps you feeling full longer, while adequate fat intake supports hormone production. Tracking macros rather than just calories gives you more control over whether you lose fat versus muscle, how energized you feel during workouts, and how well your body functions during a diet.
Which diet preset should I choose for my goals?
The best diet preset depends on your goals and lifestyle. For general health and fitness, the Balanced preset (40% carbs, 30% protein, 30% fat) works well for most people. If you are focused on fat loss while preserving muscle, High Protein (30% carbs, 40% protein, 30% fat) or Low Carb (25% carbs, 40% protein, 35% fat) are popular choices. The Ketogenic preset (5% carbs, 25% protein, 70% fat) is designed for those pursuing a keto diet, which requires severely limiting carbohydrates to induce ketosis. The Zone Diet (40/30/30) is similar to Balanced and favored by many athletes. Start with Balanced if unsure, and adjust based on how your body responds over 2-4 weeks.
How accurate is this macro calculator?
This calculator provides science-based estimates using three well-established BMR formulas. The Mifflin-St Jeor equation, our default, is accurate within approximately 10% for most healthy adults according to the American Dietetic Association. However, individual metabolism varies based on genetics, body composition, hormonal health, medications, sleep quality, and stress levels. The calculator gives you an excellent starting point, but you should treat the results as an initial target and adjust based on real-world results over 2-4 weeks. If you are not seeing expected changes in weight or body composition, try adjusting calories by 100-200 in either direction while keeping your macro ratios consistent.
What is the difference between Mifflin-St Jeor, Harris-Benedict, and Katch-McArdle formulas?
The Mifflin-St Jeor equation (1990) is the most widely recommended BMR formula, using weight, height, age, and sex. It is accurate for approximately 82% of people within a 10% margin. The Revised Harris-Benedict equation (1919, revised 1984) uses the same variables but was developed with older population data and tends to slightly overestimate BMR. The Katch-McArdle formula takes a different approach by using lean body mass instead of total body weight, making it potentially more accurate for individuals who know their body fat percentage, especially those who are very lean or very muscular. If you know your body fat percentage, Katch-McArdle may give you the most personalized result.
How many meals per day should I eat for optimal results?
Research shows that total daily macro and calorie intake matters far more than meal frequency for body composition and weight management. Whether you eat 2, 3, 4, 5, or 6 meals per day, your results will be similar as long as total intake remains the same. That said, meal frequency can affect practical factors like hunger management, energy levels throughout the day, and convenience. Some people prefer 3 larger meals for simplicity, while others find 5-6 smaller meals help control appetite and maintain steady energy. Athletes and those building muscle may benefit from spreading protein intake across 4-5 meals to maximize muscle protein synthesis. Choose a meal frequency that fits your schedule and helps you consistently hit your daily macro targets.
Is it safe to follow an extreme weight loss plan?
Extreme weight loss plans creating a 1000-calorie daily deficit should be approached with caution and ideally under medical supervision. While a 2 lb per week loss rate can be safe for individuals with significant weight to lose, it can cause muscle loss, metabolic adaptation, nutrient deficiencies, fatigue, and hormonal disruption in others. Most nutrition experts recommend a moderate deficit of 500 calories per day (approximately 1 lb per week) as the safest sustainable approach. Never eat below your BMR for extended periods, as this can significantly slow your metabolism. If you have existing health conditions, are pregnant or nursing, or are under 18, consult a healthcare provider before starting any calorie-restricted diet.